Application of RP-HPTLC and Oscik’s Equation for the Evaluation of Lipophilic Properties of Selected Biologically Active Compounds

The aim of this study was to compare different methods including theoretical based on various computer software as well as simple thin-layer chromatography in reversed phase system in the determination of lipophilicity of various classes of biologically active compounds, such as fatty acids, esters of nicotinic acid and also bile acids. The lipophilicity descriptor expressed as partition coefficient (logP) predicted by five computational algorithms (AlogPS, IAlogP, ClogP, logPKOWWIN, xlogP) and also experimental value of logP (determined by shakeflask method) which is available for selected of examined compounds belonging to esters of nicotinic acid and also bile acids can provide useful information about lipophilic character of these active compounds in their preliminary study. Experimentally determined retention parameter (RM) by means of RP-HPTLC method using binary system methanol-water on silica gel RP-18WF254 is applicable to predict other lipophilicity parameters denoted by RMWS and RMWO which have been calculated accordance with Soczewinski-Wachtmeister's and Oscik's equations, respectively. The results obtained in present study demonstrate that RMWO may be a good alternative in describing of the lipophilic character of biologically active compounds with higher lipophilicity (i.e., fatty acids and bile acids). In the case of active substances with lower lipophilicityRMWS proved to be more reliable than RMWO in describing their lipophilic character.